Here’s a chart from eMarketer.com that tracks the growth in digital ad spend worldwide and shows it as a percentage of total ad spend.
By 2016 digital will makeup 25% of the total ad dollars spent:
Worldwide, digital ad spending passed the $100-billion mark for the first time last year, according to new eMarketer estimates, and will increase by a further 15.1% in 2013 to $118.4 billion.
That will put worldwide digital ad spending levels—including online and mobile advertising spending, other than messaging-based formats—at 21.7% of the total spent on ads in all media this year, and on track to account for more than one-quarter of all ad spending by 2016.
I think that digital has an even greater impact on local advertising than is captured in this report because so much of local digital advertising is free of publication costs and therefore isn’t even tracked.
A dealer’s own site, his/her Facebook page, Google+ page, blog, etc., etc. are becoming a major part of a dealer’s local advertising effort yet are never accounted for in studies like this one because there isn’t any money spent on media.